This invention relates to an electric direct current arc welder with solid state components, of particularly low weight and overall size.
At present the direct current for arc welders is produced by a rotating generator in the form of a dynamo driven by an electric motor or an explosion engine, or by a current rectifier assembly provided with selenium plates or by silicon diode rectifiers. The current delivered is adjusted in accordance with the voltage and intensity characteristics appropriate to the welding work and the electrode diameter, and is adjusted by magnetic feed back in the case of rotating generators, and in the case of static generators by varying the magnetic dispersion or by inductive drops, by controlled rectifier bridges or by connecting an electronic switch in series with the arc.
Rotating generators or converters present disadvantages due to their high noise level and the necessary maintenance.
Rectifier units or static converters, while obviating the aforesaid disadvantages, are of large size and weight. This is because whatever adjustment technique is used for the arc current, the size, cost and weight of said converters are governed by the presence of a transformer fed at mains frequency, the purpose of which is both to obtain the voltage required by the process at the utilization terminals, and to isolate these latter from the mains supply.
The essential object of the present invention is to provide a direct current arc welder with solid state components, of particularly low weight and size.
A further object of the present invention is to provide a direct current arc welder with functional and structural characteristics of such nature that there do not exist power limitations in relation to its uses.
Another object of the present invention is to obtain high efficiency by reducing energy dissipation.